tests.nixpkgs-check-by-name: Don't test invalid Nix files

Since https://github.com/NixOS/nixpkgs/pull/279892, there's a separate
check that makes sure all changed Nix files evaluate. To not trigger
that, we need to remove all invalid Nix expressions from the tests.

pkgs/test/nixpkgs-check-by-name/src/references.rs

@@ -106,6 +106,10 @@ fn check_nix_file(
 
     let root = Root::parse(&contents);
     if let Some(error) = root.errors().first() {
+        // NOTE: There's now another Nixpkgs CI check to make sure all changed Nix files parse
+        // correctly, though that uses mainline Nix instead of rnix, so it doesn't give the same
+        // errors. In the future we should unify these two checks, ideally moving the other CI
+        // check into this tool as well and checking for both mainline Nix and rnix.
         return Ok(NixpkgsProblem::CouldNotParseNix {
             relative_package_dir: relative_package_dir.to_path_buf(),
             subpath: subpath.to_path_buf(),

pkgs/test/nixpkgs-check-by-name/tests/multiple-failures/expected

@@ -6,7 +6,6 @@ pkgs/by-name/aa: This is a file, but it should be a directory.
 pkgs/by-name/ba/bar: This path is a file, but it should be a directory.
 pkgs/by-name/ba/baz: "package.nix" must be a file.
 pkgs/by-name/ba/foo: Incorrect directory location, should be pkgs/by-name/fo/foo instead.
-pkgs/by-name/ba/foo: File invalid.nix could not be parsed by rnix: unexpected token at 28..29
 pkgs/by-name/ba/foo: File package.nix at line 2 contains the path expression "/bar" which cannot be resolved: No such file or directory (os error 2).
 pkgs/by-name/ba/foo: File package.nix at line 3 contains the path expression "../." which may point outside the directory of that package.
 pkgs/by-name/ba/foo: File package.nix at line 4 contains the nix search path expression "<nixpkgs>" which may point outside the directory of that package.

pkgs/test/nixpkgs-check-by-name/tests/multiple-failures/pkgs/by-name/ba/foo/invalid.nix

@@ -1 +0,0 @@
-this is not a valid nix file!

pkgs/test/nixpkgs-check-by-name/tests/multiple-failures/pkgs/by-name/ba/foo/package.nix

@@ -1,6 +1,6 @@
 { someDrv }: someDrv // {
-  escape = /bar;
-  escape = ../.;
+  escapeAbsolute = /bar;
+  escapeRelative = ../.;
   nixPath = <nixpkgs>;
   pathWithSubexpr = ./${"test"};
 }

pkgs/test/nixpkgs-check-by-name/tests/ref-parse-failure/default.nix

@@ -1 +0,0 @@
-import <test-nixpkgs> { root = ./.; }

pkgs/test/nixpkgs-check-by-name/tests/ref-parse-failure/expected

@@ -1 +0,0 @@
-pkgs/by-name/aa/aa: File invalid.nix could not be parsed by rnix: unexpected token at 28..29

pkgs/test/nixpkgs-check-by-name/tests/ref-parse-failure/pkgs/by-name/aa/aa/invalid.nix

@@ -1 +0,0 @@
-this is not a valid nix file!

pkgs/test/nixpkgs-check-by-name/tests/ref-parse-failure/pkgs/by-name/aa/aa/package.nix

@@ -1 +0,0 @@
-{ someDrv }: someDrv